My son has a 1998 blazer with about 180k miles on it. He has experienced overheating and coolant loss. I had him check the oil and he found coolant in it. I suspect a lim and will verify with a compression check when I get the vehicle in my garage.

Here is the question. I have a brand new 4.3l long block sitting in my garage. 600 miles on it before my daughter totaled the blazer it was in.

Would you guys swap the engine ( a real pain in the rear due to access to the transmission bolts). Or would you replace the LIM gasket first and see if the bearings hold up in the engine.

Thanks,

Kevin

 

If it were me, and I already had the engine, I'd just go ahead with the good engine.

And I'm not a fatalist on bearings, either.

It's just that you know the whole setup is good so it's worth the extra work.. plus there's info here on how to make getting at those top bolts less painful

 

I second that...use the spare...rebuild the pulled one in time.
win win

 

The doner engine is from a 96 going into a 98. Both are 4wd, 4 door units. Anything I should consider on the swap that is year specific?

 

While 200K is nothing for this engine (with good oil in the crankcase at all times) metal wise but the oil seal gaskets do start leaking. We just swapped an 119K mile 98 4WD Auto Blazer W eight digit VIN into a 98 2WD 5-speed S10 with X VIN with ZERO physical, electrical or computer issues. I do think you are fine going with the 96 long block.

I would do the intake manifold gaskets before the install just because they WILL fail. We stripped the 119K used engine down to a long block (purchased complete even with AC compressor) and went back together with new pan up gaskets. The 1998 119K engine out of the Blazer was wet from valve covers down including the oil pan itself. The pulled engine had 524,xxx miles on it and while there was ZERO cylinder block wear the oil pan gasket came apart in pieces. The OEM intake manifold gaskets on the 119K engine looked like wet cardboard and would have started leaking in the near future.

 

I opted to replace the LIM. Not that hard of a job really. About two hours to disassemble and another 2 to put it back together. The real time killer was cleaning the goop out of the engine. Close to four hours before I had it fully clean.

Only thing left is to get the cmp retard set properly. Didn't check it before I pulled the engine apart, but I can only adjust between -11 and -9 degrees. Back at it later. I'm open to ideas on how to get a little more range.

Kevin

 

To adjust your camshaft retard to spec, (zero + or - 2 degrees) remove the distributor from the engine, remove the hold down bracket and toss it in the trash. Get yourself a high performance, chrome plated Mr. Gasket SBC distributor hold down bracket, part #1009 for $5 Buy Mr. Gasket Distributor Hold Down HP 1009 at Advance Auto Parts_____ Put her back together and PRESTO ! Camshaft retard is now fully adjustable.

 

Hopefully the LIM gasket works, but depending on how long coolant has been in the oil the main bearings could be on their way out. but if you have to replace the engine, the easiest way to take it out is to take the front end off (core support and everything attached) then pull the engine and tranny out as one.

Taking the front clip off is a lot easier than it appears, and makes life way easier. I just had to pull an engine out of a 98 Jimmy and this method helped a lot.